Holding structure for robotic arm

ABSTRACT

An exemplary holding structure used for holding an object that defines a latching hole, includes a main body, a pressing member received in the main body, and two latching members. The main body includes a lodging portion for being lodged into the latching hole of object and two receiving holes are defined in the lodging portion. The latching members are received in the receiving holes. The pressing member is configured to press the latching members to partially extend out of the at least two receiving holes for holding the object. The pressing member is capable of disengaging from the at least two latching members for releasing the object from the lodging portion.

BACKGROUND

1. Technical Field

The present disclosure generally relates to holding structures, andparticularly, to a holding structure for a robotic arm.

2. Description of the Related Art

Presently, robots are widespread in automatic production devices. Arobotic arm is an important part of a robot. The robotic arm may includea holding structure for gripping an object, e.g., a workpiece. One suchholding structure generally includes a plurality of gripping fingersmounted on a control rod. When the object needs to be gripped by therobotic arm, opening and closing movements of the gripping fingers areactuated by a drive module. However, the gripping fingers generallyoccupy a relatively large space. In addition, the drive module foractuating opening and closing movements of the gripping fingers iscomplex and further increases the weight and the volume of the holdingstructure.

Therefore, a new holding structure for a robotic arm is desired in orderto overcome the above-described shortcomings.

SUMMARY

A holding structure used for holding an object that defines a latchinghole, includes a main body, a pressing member received in the main body,and two latching members. The main body includes a lodging portion forbeing lodged into the latching hole of object and two receiving holesare defined in the lodging portion. The latching members are received inthe receiving holes. The pressing member is configured to press thelatching members to partially extend out of the two receiving holes forholding the object. The pressing member is capable of disengaging fromthe two latching members for releasing the object from the lodgingportion.

Other advantages and novel features will become more apparent from thefollowing detailed description when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the drawings are not necessarily drawn to scale, theemphasis instead being placed upon clearly illustrating the principlesof the present holding structure for a robotic arm. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a partially exploded, isometric view of an embodiment of aholding structure for a robotic arm.

FIG. 2 is a cross-sectional view of the holding structure in FIG. 1

FIG. 3 is an assembled, isometric view of the holding structure in FIG.1, and showing an object need to be held by the holding structure.

FIG. 4 is cross-sectional view of the holding structure with the objectheld by the holding structure.

DETAILED DESCRIPTION

Referring to FIG. 1, one embodiment of a holding structure 100 for arobotic arm, includes a main body 20, a pressing member 30, a resilientmember 40, a fastening member 50, a cylinder shaft 60, a seal lid 70, acylinder body 75, three latching members 80, and a fixing member 90. Thecylinder shaft 60, the seal lid 70, and the cylinder body 75cooperatively form a pneumatic cylinder. The cylinder body 75communicates with a pneumatic device (not shown) for receiving gas fromthe pneumatic device.

The main body 20 includes a lodging portion 22 adjacent to an end of themain body 20 and a conical portion 24 extending out from an end of thelodging portion 22. The main body 20 defines a stepped through hole 26extending along an axis of the main body 20. A diameter of a portion ofthe through hole 26 in the conical portion 24 is smaller than thediameter of other portions of the through hole 26. The lodging portion22 is shaped as a substantially hollow cylinder and defines threereceiving holes 28 distributed evenly in a cylindrical side surface. Thereceiving holes 28 are circular holes communicating with the throughhole 26, and are configured to receive the latching members 80.

The pressing member 30 includes a cylindrical portion 322, a pressingportion 324 formed at an end of the cylindrical portion 322, and athreaded hole 32 extending through the main portion and the pressingportion 324. The pressing member 30 is capable of sliding in the throughhole 26 of the main body 20. The pressing portion 324 is shaped as aconical frustum-shaped portion for pressing the latching members 80 tomove outwards. Furthermore, the latching member 80 may also press thepressing portion 324 to move upwards into the though hole 26 of the mainbody 20. In other words, a motion of the pressing member 30 and a motionof the latching member 80 can be changed by each other.

In one embodiment, the resilient member 40 may be a helical compressionspring. It should be pointed that, the resilient member 40 may also beother springs such as a compression rubber spring.

The fastening member 50 is cylindrical in shape and defines a shaft hole52. The fastening member 50 is configured to tightly engage in thethrough hole 26 of the main body 20.

The cylinder shaft 60 is configured to be partially received in the mainbody 20. The cylinder shaft 60 includes a piston 62 and a shaft portion64. The piston 62 is fixed or formed on a first end of the shaft portion64. A threaded portion 642 is formed at a second end of the shaftportion 64 away from the first end. The threaded portion 642 isconfigured to be screwed in the threaded hole 32 of the pressing member32.

The cylinder body 75 is substantially a cylindrical barrel. The cylinderbody 75 includes a closed end and an opened end opposite to the closedend. The cylinder body 75 defines a first gas valve 76 adjacent to theclosed end and a second gas valve 78 adjacent to the opened end. The gasvalves 76, 78 are configured to receive gas from the pneumatic device.The first end of the cylinder shaft 60 with the piston 62 are configuredto be received in the cylinder body 75 and the opened end of thecylinder body 75 can be sealed by the seal lid 70.

The latching members 80 are rotatable balls. A diameter of each latchingmember 80 is slightly greater than a diameter of each receiving hole 28.

The fixing member 90 comprises a screw including a head portion 92 and athreaded portion (not labeled) extending from the head portion 92. Thethreaded portion of the fixing member 90 is configured to engage in thethreaded hole 32 of the pressing member 30.

Referring to FIGS. 1 and 2 together, the holding structure 100 may beassembled as follows. The latching members 80 are inserted into thethrough holes 26 of the main body 20, and then received in the receivingholes 28 of the main body 20, correspondingly. The pressing member 30 isreceived in the through hole 26 of the main body 20 and presses thelatching members 80 so that the latching members 80 partially extend outof the receiving holes 28 of the main body 20. The resilient member 40is received in the through hole 26 of the main body 20 and abuts thepressing member 30. The fastening member 50 tightly engages in thethrough hole 26 of the main body 20 and abuts the resilient member 40.The shaft portion 64 of the cylinder shaft 60 is consecutively passedthrough the shaft hole 52 of the fastening member 50 and the resilientmember 40. The threaded portion 642 of the cylinder shaft 60 is screwedin an upper portion of the threaded hole 32 of the pressing member 30,thus the cylinder shaft 60 is fixed relative to the pressing member 30.The threaded portion of the fixing member 90 is screwed in a lowerportion of the threaded hole 32 of the pressing member 30. The first endof the cylinder shaft 60 together with the piston 62, are received inthe cylinder body 75 and the opened end of the cylinder body 75 issealed by the seal lid 70, thus the cylinder body 75 is partitioned intoa first chamber 751 and a second chamber 752. The first gas valve 76communicates with the first chamber 751and the second gas valve 78communicates with the second chamber 752.

Referring to FIG. 3, an object 110 needs to be held by the holdingstructure 100 defines a plurality of latching holes 112. A side wall ineach latching hole 112 defining a latching groove 1122. Generally, twoholding structures 100 are used for holding the object 110, and thenumber of the holding structures 100 may correspond to the number of thelatching holes 112. The principle of using one of the holding structures100 to hold the object 110 will be illustrated as follows.

When the object 110 is to be held by the holding structure 100, thelodging portion 22 of the main body 20 is aligned with one of thelatching holes 112 of the object 110. At this time, the pressing member30 presses the latching members 80, and the latching members 80partially extend out of the receiving holes 28 of the main body 20. Apressure in the second chamber 752 is increased by injecting gas via thegas valve 78 or a pressure in the first chamber 751 is decreased bydrawing the gas out of the first chamber 751 via the gas valve 76. Thepressure in the first chamber 751 becomes lower than a pressure in thesecond chamber 752, thus a pressure difference is created between thefirst and second chambers 751,752. The piston 62 with the shaft portion64 is moved towards the closed end of the cylinder body 75 because ofthe pressure difference. The shaft portion 64 drives the pressing member30 and the fixing member 90 to move towards the closed end of thecylinder body 75, thus compressing the resilient member 40 and, as aresult, the pressing member 30 disengages with the latching members 80.The lodging portion 22 of the main body 20 is lodged into one of thelatching holes 112 of the object 110.

When the lodging portion 22 of the main body 20 is lodged into thelatching hole 112 of the object 110, the latching members 80 are drawnback into the receiving holes 28 of the main body 20 by the side wall ofthe latching hole 112. The lodging portion 22 of the main body 20 ismoved until the latching members 80 reach the latching groove 1122. Thepressure in the first chamber 751 is increased by injecting gas from thegas valve 78 or the pressure in the second chamber 752 is decreased bydrawing gas out of the first chamber 751 via the gas valve 76, thus thepressure in the first chamber 751 becomes higher than the pressure inthe second chamber 752. Then, the piston 62 with the shaft portion 64 ismoved towards the opened end of the cylinder body 75. The shaft portion64 drives the pressing member 30 and the fixing member 90 to move awayfrom the closed end of the cylinder body 75, thus the latching members80 are pushed by the pressing member 30 to partially extend out of thereceiving holes 28 of the main body 20 and engage in the latching groove1122. Therefore, the object 110 is held by the holding structure 100.

When the object 110 needs to be released from the holding structure 100,the pressure in the second chamber 752 is increased again by injectinggas from the gas valve 78 or a pressure in the first chamber 751 isdecreased again by drawing gas out of the first chamber 751 via the gasvalve 76. The shaft portion 64 with the pressing member 30 is moved tocompress the resilient member 40 such that the pressing member 30disengages with the latching members 80. When the holding structure 100is moved away from the object 110, the latching members 80 are drawnback into the receiving holes 28 of the main body 20 and slide out ofthe latching groove 1122. Therefore, the object 110 is released from theholding structure 100.

In an alternative embodiment, the cylinder body 75 can be omitted, butthe robotic arm defines a receiving chamber for receiving the cylindershaft 60. When the cylinder shaft 60 is received in the receivingchamber, the receiving chamber is partitioned into two chambers. Thecylinder shaft 60 can be moved upwards or downwards by injecting gas ordrawn gas out of one of the first and second chambers 751, 752.

It should be pointed out that, the cylinder shaft 60 of the holdingstructure 100 may not connected to the cylinder body 75. When thelodging portion 22 of the main body 20 is inserted into the latchinghole 112 of the object 110, the latching members 80 are drawn back intothe receiving holes 28 of the main body 20 by the side wall of thelatching hole 112 and press the pressing portion of the pressing member30 to move upwards long the though hole 26 of the main body 20. Theresilient member 40 is compressed by the pressing member 30. When thelatching members 80 reach the latching groove 1122 of the object 110,the resilient member 40 creates a force to push the resilient pressingmember 30 to move downwards, thus to press the latching members 80 topartially engage in the latching grooves 1122 of the object 110.Therefore, the object 110 is held by the holding structure 100. When theobject 110 needs to be released from the holding structure 100, the headportion 92 is pushed to move upwards or the cylinder shaft 60 is pulledupwards. Therefore, the latching members 80 are drawn back into thereceiving holes 28 of the main body 20 by the side wall of the latchinghole 112 and slide out of the latching groove 1122 of the object 110.Then, the object 110 is released from the holding structure 100.

By controlling the latching members 80 to engage in or slide out of thelatching groove 1122 of the object 110, the holding structure 100 cangrasp and release the object 110. Therefore, the holding structure 100occupies a relatively small space and has a relatively simple structure.

It should be pointed out that, the fixing member 90 may be omitted. Thelatching members 80 are not limited to rotatable spheres. Each latchingmember 80 may be shaped as a cylinder having a first spherical portionformed at a first end for abutting the pressing portion 324 of thepressing member 30 and a second spherical portion formed at an secondend for engaging in the latching groove 1122 of the object 110. A numberof the latching members may not be three, for example two or more thanthree.

It is believed that the present embodiments and their advantages will beunderstood from the foregoing description, and it will be apparent thatvarious changes may be made thereto without departing from the spiritand scope of the disclosure or sacrificing all of its materialadvantages, the examples hereinbefore described merely being exemplaryembodiments of the disclosure.

1. A holding structure for holding an object that defines a latchinghole, the holding structure comprising: a main body comprising a lodgingportion for being lodged into the latching hole of object, and at leasttwo receiving holes defined in the lodging portion; a pressing memberreceived in the main body; and at least two latching members received inthe least two receiving holes correspondingly; wherein the pressingmember is configured to press the at least two latching members topartially extend out of the at least two receiving holes for holding theobject, and the pressing member is capable of disengaging with the atleast two latching members for releasing the object from the lodgingportion.
 2. The holding structure of claim 1, further comprising acylinder shaft partially received in the main body, wherein the pressingmember is fixed to the cylinder shaft, the cylinder shaft is capable ofsliding along the main body so that the pressing members is driven topress the at least two latching members or disengage with the at leasttwo latching members.
 3. The holding structure of claim 2, furthercomprising a cylinder body, wherein the cylinder shaft comprises apiston and a shaft portion, the piston is formed on a first end of theshaft portion, and the piston is received in the piston to partition thecylinder body into two chambers.
 4. The holding structure of claim 3,wherein the cylinder shaft further comprises a threaded portion formedat a second end of the shaft portion away from the first end, thepressing member defines a threaded hole, and the threaded portion isscrewed in the threaded hole.
 5. The holding structure of claim 3,wherein the holding structure further comprises a resilient member, anda fastening member, the resilient member is sleeved on the shaft portionof the cylinder shaft and received in the main body for abutting thepressing member, and the fastening member is fixed to the main body andabuts the resilient member.
 6. The holding structure of claim 5, whereinthe resilient member is a compression spring.
 7. The holding structureof claim 5, wherein the lodging portion is adjacent to an end of themain body, and the main body further comprises a conical portionextending from the lodging portion.
 8. The holding structure of claim 7,wherein the main body defines a stepped through hole extending along anaxis of the main body, a diameter of a portion of the through hole inthe conical portion is smaller than the diameter of other portions ofthe through hole; the pressing member, the resilient member, and thefastening member are consecutively received in the through hole.
 9. Theholding structure of claim 8, wherein the holding structure furthercomprises a fixing member partially inserted into the through hole ofthe main body from the conical portion and fixed to the pressing member.10. The holding structure of claim 8, wherein the receiving holes arecircular holes communicating with the through hole, the latching membersare rotatable spheres, and a diameter of each of the latching members isgreater than a diameter of each receiving hole.
 11. The holdingstructure of claim 1, wherein the pressing member comprises a pressingportion formed at an end thereof, and the pressing portion is shaped asa conical frustum-shaped portion for abutting the at least two latchingmembers.
 12. A holding structure for holding an object that defines alatching hole, the holding structure comprising: a main body comprisinga lodging portion for being lodged into the latching hole of object anda through hole extending along an axis of the main body, wherein thelodging portion is adjacent to an end of the main body and defines threereceiving holes communicating with the through hole; a pressing memberreceived in through the main body; and three latching members receivedin the receiving holes correspondingly; wherein the pressing member isconfigured to press the at least two latching members to partiallyextend out of the receiving holes for holding the object, and thepressing member is capable of disengaging from the latching members forreleasing the object from the lodging portion.
 13. The holding structureof claim 12, further comprising a cylinder shaft partially received inthrough hole of the main body, wherein the pressing member is fixed tothe cylinder shaft, the cylinder shaft is capable of sliding along thethrough hole of the main body for driving the pressing members to pressthe latching members or disengage with the latching members.
 14. Theholding structure of claim 13, further comprising a cylinder body,wherein the cylinder shaft comprises a piston and a shaft portion, thepiston is formed on an end of the shaft portion, and the piston isreceived in the piston to partition the cylinder body into two chambers.15. The holding structure of claim 14, wherein the holding structurefurther comprises a resilient member, and a fastening member, theresilient member is sleeved on the shaft portion of the cylinder shaftand received in the through hole of the main body for abutting thepressing member, and the fastening member is fixed in through hole ofthe main body and abuts the resilient member.
 16. The holding structureof claim 15, wherein the main body further comprises a conical portionextending from the lodging portion, the through hole extends through theconical portion, a diameter of a portion of the through hole in theconical portion is smaller than the diameter of other portions of thethrough hole.
 17. The holding structure of claim 16, wherein the holdingstructure further comprises a fixing member partially inserted into thethrough hole of the main body from the conical portion and fixed to thepressing member.
 18. The holding structure of claim 12, wherein thereceiving holes are circular holes, the latching members are rotatablespheres, and a diameter of each of the latching members is greater thana diameter of each receiving hole.
 19. The holding structure of claim12, wherein the pressing member comprises a pressing portion formed atan end thereof, the pressing portion is shaped as a conicalfrustum-shaped portion for abutting the latching members.